1. Field
Embodiments relate to a robot including a plurality of joints, each of which is driven by a motor.
2. Description of the Related Art
In general, a mechanical device which performs motion similar to human motion using an electrical or magnetic mechanism is called a robot. Early robots included manipulators used for automated or unmanned tasks in manufacturing plants or industrial robots such as transportation robots, and performed dangerous tasks, simple repeated tasks or tasks requiring large force in place of a human. Recently, research into a humanoid robot, which has joints similar to those of a human, coexists with a human in a working and living space of the human and provides various services, has been actively conducted.
Most manipulators, transportation robots and humanoid robots are driven by motors. In particular, if a robot has joints, a motor is provided to each joint and each joint is moved by driving the motor. The movement of a motor-based device may be stopped in the following two cases: a first case where normal control is intentionally performed and a second case where an internal or external power source of the device is unintentionally and suddenly cut off. The first case is not problematic because the stoppage of the operation of the device is recognized in advance. In the second case, if the power source is suddenly cut off during the operation of the device, the motor falls to a free running state. In a movable device using multiple joints, such as a walking robot, the stoppage of the operation of the device due to unintended interruption of the power source may hinder the pursuit of the purpose of the operation of the device and obtain an unexpected result.